Hot Air Impingement Drying Ovens
topic
Hot air impingement dryers direct high-velocity heated air at 80 to 180 degrees Celsius through nozzle arrays at 25 to 50 metres per second perpendicular to the coated substrate surface, providing convective heat transfer coefficients 3 to 5 times higher than recirculation hot air without impingement, enabling higher line speeds or shorter oven lengths for the same drying performance while maintaining even drying across the full substrate width.
Role
Achieves high drying rates for water-based and solvent-based coating systems through the high convective heat transfer of impingement air that reduces drying time and oven length compared to conventional recirculation drying, with impingement nozzle design and air velocity optimisation providing the maximum drying rate compatible with avoiding surface skinning of the drying coating that would trap residual solvent or water and cause surface defects.